Pellet type heat exchanger



Nov. 3, 1959 H. KARLSSON 2,911,198

PELLET TYPE HEAT EXCHANGER Filed Sept. 28, 1956 i normal flow of uid therethrough.

A 2,911,198 Platentedr. Novi :3; 1 959 Vrice g 4,911,198? l I PELLET'TYPE-matrEXCHANGE@ Hilmer. KarlssomfWellsville, AN-..Y.,,.assigner to Th'e Preheater CoporatiomNew Yrk,.N.Y., acorporation of- New York VApplication vSeptember 2.8;: 12956; SerialfNo. l6125643 kp s c1aims.(c l.-zs7: fss)' almass of nelydivided'particles orpelletsbe-placed in heat exchangerelationship by passing a fluid-upwardly through a contacting vessel containing a descending stream of pellets. Arrangements for distributing and retarding Vthe ow of pellets through a contacting vessel have been suggested whereby a seriesof horizontal bars are placed transverse to the descending pellets vand the In various applications of this general type operational temperatures are limited chiefly by the characteristics of the material used for the transverse rods, and in view thereof an important object of this invention is to provide an arrangement lets vsimultaneously serve the dual function-of heat transfer medium and cleaning agent.

These and other objects-of my invention will become more apparent when'read in" conjunction with the accom` panying drawingsk in which:

Figure 1 isa diagrammatic sectional elevation of a contacting chamber for a pellet type heat exchanger or chemical reactor of the Atype herein defined.

Figure 2 is a section on line 2-2 of Figure 1.

Figure 3 is a section of line 3-3 of Figure 1. Y

Figure 4 is a view similar to Figure 3 of ajmodie form of the invention. l

whereby cooling means introduced to the transverse rods K l,

permits operational temperatures well above the-usual combined pellet and tubular heat vexchanger wherein pelt Referring particularly to Figure 1 of the drawings, the v pellet chamber 10 comprises an upright elongate shell or housing 12 closedA at its upper and lower ends and having a pellet inle't duct 14 for the admission of pellets from a hopper 40 to the upper portion of the chamber and an outlet duct 16 adapted to withdraw the pellets from the bottom of the chamber. A pair of tube-sheets 18'bonded to the inner wallsl of the chamber 10 in spaced i relation provide a pair of header sections 22 interconnected by a series of vtubular members 24. An inlet 26 in the lower portion of the housing 12 admits hot gas to the lower portion of the chamber 10 where it flows upward over the tubular members Z4 and in contact with the falling pellets to an outlet 28 where it is exhausted from the chamber. In addition to the ports leading into chamber 10, header sections 22 are provided with a cold t air inlet 32 and a heated air outlet 34 at opposite ends l 2 thereof to permitfthe 'circulation'` of'affluid through the tubes` andi-'their fadjoininglrheaders:

Theindividual 'headers sections 122 .are divided', by= a series oftransversebaiiles36iinto a plurality ofV subjacent chambers, opposite ones offwhich'` are linkedv bythe v tubular'members24. Oppositebaes 36.. are staggered in orderthat fluidfenteringinlet 32is forced to ow serially through the" interconnected banks oftubular members24 to the spacedfoutlet 34- infcontinuous heat exchange relation'with lthe vhot vgas owing .throughlchaml y A pellet distributingfmeans38`comprising ai mesh; grating orfaseries `off-spaced elongate members is arf ranged tov 'distributeathe pelletswhile-l simultaneously retardingl their l descent from pellet :reservoir-40.1A

Referring; moreparticularly tok Figure 3 ofr the drawing; a'longitudina'l section of-=the= pellet contacting chamber'isIar-ranged-to. showla seriesof cylindrical tubes arranged infsta'g'gered relation irrparallel rows sothat tubes in alternate-rows llient-vertical alignment to presenta tortuous .pathi for theemovement 'of' pellets -and -gases through" :the -interst-ices-l therebetween- By suchA device the fgravitating pellets and the lcontra-flowing`4 gases e are simultaneously retarded and mixed'so as to provide a high rate of heat transfer therebetween.

In Figure 4 a modified form shows aA series of streamv line tubes 25 arranged similar to those of Figure 3 to provide for the passage of uid therethrough in heat exchange relation with a fluid flowing thereover. The streamline tubes are disposed horizontally with the broad edge 27 thereof presented upward to afford a greater surface area to the descending pellets. By this arrangement resistance to the descending pellets is increased substantially While the resistance to fluid flowing upward thereover remains substantially unchanged.

In operation the pellet reservoir 40 is provided with a continuous supply of pellets from a non-illustrated source of supply while the outlet 16 is arranged to direct the pellets to a predetermined destination where they are to be further processed. Hot gases from inlet 26 are directed upward over the transverse tubular members 24 in simultaneous heat exchange relation with the pellets gravitating from inlet 40 and the cool uid circulating serially through tubes 24 from inlet 32 to outlet 34.

. Fluid circulating from inlet 32 through tubes 24 to outlet 34 may be utilized solely because of its cooling effect upon the tubes 24 and tube sheets 118. However, the degree of heat rise in this fluid may predicate its further use in the heating cycle of which it may be a part. Accordingly, by this arrangement the temperature effectively removes the deposits while simultaneously permitting the pellets to serve as a heat transfer medium. By maintaining the heat transfer surfaces free from deposits of foreign particles theefficiency of the heat transfer through the tubes 24 to the cooling fluid therein is not permitted to degenerate with use.

While this invention has been described with reference to the rectangular housing illustrated in the drawing, lit is evident-that a cylindrical housing may be used or that other minor changes may be made without departing from the spirit of the invention, rand it is intended that all'matter contained in this description or shown in the accompanying draivin'gs shall be interpreted as illusti'ative and not in a limiting sense.

What is claimed is:

l. Pellet heat exchange apparatus or the like including a' closed :upright housing'fhaving" a pellet linlet port at its upper end and a pellet Youtlet port at its remotely spaced end arranged to permit the descentV of pellets therethrough; a fluid inlet port'in said housing ,adjacent the pellet outlet port and a iluid outlet port adjacent the pellet inlet port adapted to direct a fluid through the housing in opposition to the descending pellets; a plurality of restraining members extending across the housing, each including a broad Yedge facing upward and arelatively narrow edge facing downward to present a f maximum resistance to the descending pellets `and a minimum resistance to theascending fluid.

v 2.A Pellet heat exchange apparatus or the like including a closed upright housing having a pellet inlet port at its upper end and a pellet outlet port at its remotely spaced end arranged to permit the descent of pellets therethrough; a uid inlet port in said housing adjacent the pellet outlet anda uid outlet port adjacent the pellet inlet adapted to direct an ascending fluid through the housing in opstraining' tubes.' f

position to the descending pellets; and restrainingnmeans 1 disposed across the housing having a broad edge thereof directed toward the descending pellets and a narrow edge directed toward the ascending fluid to thereby significantly retard the fallof pellets'while offering resistance to the ascending fluid,l

3. Pellet heat exchanger apparatus or the like including a closed upright housing having a pellet inlet port at its upper end and a pellet outlet port at its remotely spaced end adapted to permit the descent of pellets therethrough; a iluid inlet port in, said housing adjacent the pellet outlet port and a iluidoutlet port adjacent the pellet inlet'jport adapted to directv an ascending uid through the housing in opposition to the descending pellets; streamline restraining tubes Ydisposedv across the housing with a broad edge thereof directed toward the descending pellets and a relatively narrow edge directed towardthe ascending uid to thereby retard the descending pellets Whilek offering, minimum resistance to the ascending fluid; and Vheader 4means at opposite sides of the housing adapted to provide intermediate uid chambers receiving a cooling uid circulating through the re- K References the leiv-of this Vpat-ent UNITED `srirrns PATENTS 1,789,880 Price .lan.'20, 1931 1,958,364 i Govers v May 8, Y1934 2,379,195

Simpson et al, v June 26, 1945` 

